将linux运行时间格式成易读格式的php代码

<?php
    $exec = shell_exec('uptime');
    $uptime = explode(' up ', $exec);
    $uptime = explode(',', $uptime[1]);
    if (strpos($uptime[0], 'day')) {
        $time = explode(':', $uptime[1]);
        echo('Current system uptime is ' . $uptime[0]. ', ' . $time[0] . ' hours, ' . $time[1] . ' minutes');
    } elseif (strpos($uptime[0], ':')) {
        $time = explode(':', $uptime[0]);
        echo('Current system uptime is ' .  $time[0] . ' hours, ' . $time[1] . ' minutes');
    } else {
        $time = explode(' ', $uptime[0]);
        echo('Current system uptime is ' .  $time[0] . ' minutes');
    }

?>